This invention relates generally to the field of wire movement and more specifically to a machine for pulling wire through a conduit.
The simple act of pulling wire through conduit is an art of continuously growing importance as on-the job muscle strain and long term back injury become increasingly common in installation of new communications and power systems. Generally speaking, a new building or structure must be internally wired and that internal wiring then interfaced with an external power or communications grid. For electrical power systems, the interface point is usually an electric meter box, affixed to the exterior of the building. The incoming wires of the power grid are frequently supported by utility poles placed along a road or thoroughfare proximate the building.
Until recently, the preferred means to affect such interface has been to string the wires from utility pole to house, the wires suspended in space between the two. However, this practice is falling out of favor for numerous reasons of esthetics, obstruction, and practicality.
Wires are increasingly being run underground, particularly from utility poles to meter boxes by means of conduits. The wires remain, thus, out of sight and out of the reach of deleterious environmental conditions. The preferred configuration of the conduits is an essentially vertical extension downward to a point below the ground of sufficient depth to afford protection from previously mentioned environmental elements and thence via a substantially horizontal conduit to a point substantially below desired location, such as a meter box, and then up a substantially vertical conduit extension to the meter box location.
This gives occasion to the necessity of pulling wires through the conduit after it is placed. Because the wires are very heavy, there is significant friction between the wires and the interior of the conduit, especially at the points of transition from substantially vertical to substantially horizontal courses and vice versa. Pulling these wires through up to several hundred feet of conduit, is a very laborious and dangerous task which may require the exertion of several strong men, as presently accomplished. It is back-breaking work, and often literally results in muscle strains and injuries. Thus, a machine that is light and can easily be transported to a remote site by one person and that can facilitate the wire pulling task without this expensive, unpleasant, slow, and potentially dangerous human effort is desirable. Accordingly, a number of inventors have addressed this issue as discussed below. The instant art is an advancement over such extant technology.
U.S. Pat. No. 6,540,208 B1 by Pecot et al., discloses a method of installing cable in a conduit wherein the cable is borne through the conduit by a flow of pressurized water, the pressure and flow rate of which is carefully regulated by a complex arrangement of various elements, the whole being controlled by a central processing unit.
In substantial contrast to Pecot et al., the instant art teaches neither pressurized water nor arrangement of complex elements to direct pressurized water, nor any sort of micro-processor.
U.S. Patent Application 2002/0100898 A1 by Knoerzer et al. teaches an articulated cable puller having a boom adjustable for horizontal and vertical orientations, a rotatable base, and hydraulic cylinders to affect the articulation. The Knoerzer et al. art, is large, heavy, and must be mounted on a large vehicle.
In contrast to Knoerzer et al., the instant art employs no booms having inter-planar movement, no rotating bases, and no hydraulic cylinders. Furthermore, and in further contrast, the instant art is small, light, and easily carried by one person. In yet additional contrast to Knoerzer et al., the instant art is significantly less complex.
U.S. Patent Application 2003/0098450 A1 by Cook et al. recites a cable pulling device comprising power means (electrical), protractors to pivotably mount a frame member, a base to support the device on and against the ground, foot control means to activate or deactivate the device, a plurality of pulleys, and an articulatable bushing assembly.
In substantial contrast to Cook et al., the instant art requires no pivotable elements, no component that must be supported by or in contact with the ground, no plurality of pulleys, no foot controls and no articulating components. Furthermore, the instant art is not limited to using electrical power, but on the contrary teaches embodiments having non-electrical power means using, in fact, virtually any rotary power source that can physically fit the device. In addition, the instant art comprises fewer parts so is more easily and economically fabricated and assembled.
U.S. Pat. No. 3,514,048 by Lowery teaches a cable feed apparatus. In substantial contrast to the instant disclosure, Lowery recites a fairlead that guides a cable but does not impart motive force to a cable. The instant technology imparts pulling force at a capstan.
U.S. Pat. No. 3,952,999 by Keller et al. discloses a wire pulling apparatus having a base that must rest upon a floor, having wedges to anchor the base to a wall, and having a plurality of upright members having an axle journaled there between. In addition, Keller et al., teaches a pulley having a sheave too small to allow a cable to be set by multiple turns around it. Motive force is provided by means of human muscle.
In substantial contrast to Keller et al., the instant art teaches no base that must be supported by a floor, no means to anchor the base to a wall, and no plurality of upstanding members. In additional contrast to Keller et al., the instant art recites an energy imparting capstan having a sheave such that a line or cable may be wound around it a plurality of times and thus achieve a set. In yet further contrast to Keller et al., the instant art teaches away from using human muscle as a motive force.
U.S. Pat. No. 4,270,734 by Straight teaches an automatic wire puller having a frame with opposed sides adapted to fit between support studs, and a winch having a drum to receive and store line. In addition, the frame is contrived with sets of brackets so that the drawing force of the winch will create force against the brackets causing them to clamp against the studs. The distance over which a line may be pulled by the Straight art is limited to the capacity of the drum, thus the pulling force will decrease as the drum fills.
In contrast to Straight, the instant art teaches no frame having opposing sides that must be supported by spaced apart studs, nor any bracket arrangement requiring a plurality of brackets arranged so that a clamping force moment will be created by the turning of the winch. In addition, the instant art teaches a capstan rather than a storage drum so that the distance it may pull a line is not limited to the capacity of a drum. Also, because the capstan does not store line, the pulling force of the capstan will remain constant as increasing amounts of line are pulled in additional contrast to Straight.
U.S. Pat. No. 4,033,551 by Lindstrom teaches a wire pulling device having a portion that must be supported by a wall and another portion that must be supported by the ground. In contrast to Lindstrom, the instant art requires no support by either a wall or the ground or a floor.
U.S. Pat. No. 4,337,924 by Gebo recites a wire pulling device having a pair of stanchions joined by a cross brace, a pair of capstans, a pair of motors, a plurality of pulleys, and a pair of pull ropes. In addition, Gebo discloses a base which must be supported by the ground or a floor.
In substantial contrast to Gebo, the instant art teaches no stanchions joined by a cross brace, no plurality of pulleys, no plurality of capstans, no plurality of motors, and no plurality of pull ropes. Furthermore, the instant art is not limited to support by the ground or a floor. In further contrast to Gebo, the instant art is much less complex than Gebo and accordingly can be fabricated and assembled much more cheaply and easily than Gebo.
U.S. Pat. No. 4,635,875 by Apple discloses a line pulling device comprising a pulling element having a drum with storage means, bull wheels over which a line must be looped in “figure 8” configuration, and an oscillatory sheave. Furthermore, Apple teaches complicated arrangements to synchronize the rotating speed of a plurality of wheels and equally complex means to equalize pulling force of the wheels and hydraulic circuits.
In substantial contrast to Apple, the instant art teaches no plurality of bull wheels, no storage drum, no hydraulic circuits, no oscillating elements, no lines looped in “figure 8” configuration, and no pulling force or wheel speed synchronization means.
U.S. Pat. No. 6,691,985 B1 by El Haddad teaches an electrical wire pulling apparatus supported by brackets for attaching it to the walls of a pre-existing housing.
In contrast to El Haddad, the instant art teaches no brackets for attachment force creating means and is not limited to attachment to a pre-existing structure having walls.
U.S. Pat. No. 6,883,783 B1 by Quittschreiber teaches a machine for pulling wire through an underground conduit, the machine requiring pre-installed anchor bolts and a universal adapter plate having slots disposed to receive a plurality of patterns of anchor bolts. In contrast to Quittschreiber, the instant art teaches no universal adapter plate and is not limited to use in locations having pre-installed anchor bolts.
U.S. Pat. No. 6,367,778 B1 by Mobley et al. teaches a line pulling device having a plurality of rollers that pinch a line between them to impart pulling force to the line, the position of the rollers being adjustable to accommodate different diameters of lines, and a yoke to support the rollers. In addition, Mobley teaches communication of the rollers by means of interconnecting gears.
In contrast to Mobley, the instant art teaches no plurality of rollers to impart pulling force to a line and teaches away from pinching a line between rollers to impart pulling force to a line, but, rather teaches a capstan. In additional contrast to Mobley, the instant art teaches no adjustable rollers to accommodate different diameters of lines, no yoke to support rollers, and no rollers communicating by means of interconnected gears.
U.S. Pat. No. 5,984,273 and U.S. Pat. No. 6,286,815, both by Ray, teach wire pullers having a pivoting frame, the frame also having an “on/off” switch, a stand supported by the ground, and a drive shaft mounted by one device on a particular area of the frame, and mounting of a power device by means of another device on another area of the frame.
In contrast to both Ray patents, the instant art teaches no pivotable elements, and requires no “on/off” switch, no stand that must be supported by the ground or a floor, and no driveshaft mounted on one part of the frame and power source mounted on another part of the frame. It uses, rather, a drive shaft and power source mounted on the frame by means of one device at one location.
U.S. Pat. No. 6,286,815 B1 by Ray recites a wire puller having a frame, the frame also having a particular forearm portion, supported by a base that must be supported by the ground or a floor, a drive shaft mounted on a particular portion of the frame by another device, a power source mounted on another portion of the frame by means of another separate device, and a mounting bracket attached to the forearm portion wherein the mounting bracket further supports a means to interface with the opening of a conduit, but wherein, during operation of the device, the interface means does not bear the weight of the device or the moment force created by the pulling force and the resistance of the line.
In substantial contrast to Ray, the instant art teaches no component that must be supported by the ground or the floor, no separate portions of the frame for mounting a drive shaft and a power source, and no separate devices for mounting a drive shaft and a power source. In further contrast to Ray, the instant art teaches a mounting bracket not attached to a forearm portion, but supporting a device to interface with the opening of a conduit, the opening supporting the weight of the entire device and the moment of pulling force of the power source and resistance, in yet further contrast to Ray.
U.S. Pat. No. 4,456,225 by Lucas teaches a cable-pulling apparatus, comprising a plurality of pulleys, a plurality of yokes, a frame portion that must be supported by the ground or a floor, and means to transfer a portion of the weight of the device, the moment of force created by the pulling force, and resistance of the cable being pulled, to the lip of a conduit and/or a surface of a structure such as a junction box. Furthermore, the means to transfer the previously described moment of force to the lip of the conduit is by means of plates disposed at an angle such that points of contact between the plates and the conduit are small and constitute a very small portion of the conduit lip.
In substantial contrast to Lucas, the instant art teaches no plurality of pulleys, no plurality of yokes, nor any element that must be supported by the ground or a floor. In further contrast to Lucas, the instant art teaches force transfer to the lip of a conduit by means of an annular device that contacts substantially the entire surface of the lip of the conduit. In yet additional contrast to Lucas, the instant disclosure recites transfer of all weight of the device and all wire pulling forces to the lip of the conduit, not just a part of the forces as in Lucas.
U.S. Pat. No. 3,968,952 by Newell teaches a line pulling device having a frame with a plurality of separate sections pivotably connected in relation to each other, and horizontal support elements that support operative elements of the device.
In contrast to Newell, the instant art comprises no pivotable elements, but a frame comprising only one element, and requires no horizontal support components to support any operative parts of the instant technology.